


Pup's Knotty Probem

by lizrat66



Series: The Pet and the Vet. [10]
Category: Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: M/M, Master/Pet, Multi, Non-Consensual Body Modification, Non-Consensual Bondage, Non-Consensual Drug Use, Non-Consensual Oral Sex
Language: English
Status: Completed
Published: 2019-06-03
Updated: 2019-07-07
Packaged: 2020-04-07 11:09:40
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 5,105
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19083814
Author URL: https://archiveofourown.org/users/lizrat66/pseuds/lizrat66
Summary: Pup meets the Vet's latest guests, and gets to participate in their transformations, all be it unwillingly.





	1. Chapter 1

**Author's Note:**

> A chapter full of NON-CON, you have been warned!

A Knotty Problem for Pup.

Tony whined in pain as his stomach gurgled and cramped, the pressure of his full bladder adding to his woes. The Vet had been called away on an emergency earlier that morning before he had time to carry out his morning cleansing routine, he had also left the food pump on its high morning feeding setting. Three hours later his stomach was round and distended, his bowels full and his plugged piss hole burned.

 

Secured in his crate he could do nothing but watch as the hands slowly turned on the wall mounted clock. With each passing minute his whines grew louder, the feeding gag stopping him from out-right howling as the pain intensified. The gaseous smell of his ripe bowels had him gagging as he desperately tried not to vomit. Tears of humiliation streamed down his cheeks as his bowels finally evacuated their contents, not even his butt plug could stop the disgusting liquid from leaking out from his asshole, to drip down his thighs. 

 

The Vet was furious when he returned from the Court House, the supposed emergency turned out to be nothing more than his tame Judge, wanting him to disappear his step-daughter and her fiance, who had been found to have the latent pet gene, which would mean any child they had could potentially be a pet. The Judge’s daughter had refused to break off the engagement and the boyfriend would not agree to being sterilised, both had threatened to go public and the Judge did not want the embarrassment as he was to be nominated to become a Supreme Court Justice in six-month time.

 

A few phone calls later and the couple would supposedly be killed when their SUV crashed as they drove back from their romantic weekend mountain getaway. In reality, they would be subdued and sedated at the remote cabin where they were staying and transported to his Practice, arriving later that day. The SUV and the replacement bodies would be burned beyond recognition, with the medical examiner being paid a large amount of money to falsify the DNA tests and medical certificates confirming their deaths. The families would receive the cremated remains to bury, the Vet would gain two new projects, one of which would be returned to the Judge as his new pet once transformed beyond all recognition, the other would be put up for auction and the pair would never see each other again.

 

The stench hit him the moment he walked into the examination room, the pet was whining and shaking in his crate, thighs coated in shit, face red and puffy. He took note of the swollen stomach, the distended mound highlighting the two rows of small nipples which had formed full over the past two days.

 

“Fuck sake! Look at the state of you, pathetic mutt! As if I don’t have enough to do today, now I have to spend time cleaning you up.”

 

After pushing the crate over to the shower area, he turned the shower hose on to jet wash and blasted the caged pet with water, once Tony’s thighs were clean, he removed the urethral sound and the butt plug, glad he had put on a face mask when more shit gushed out of the pet’s gapping, hole.

 

“Dirty puppy, going to have to give you a deep cleansing enema, let’s see how much more you stomach can take, give you a good idea of how big you will get when fucked full of pups for real. Look at you, pissing yourself, bet it’s with excitement at the thought of being mounted and fucked full of pups.”

 

The pain was excruciating when the vet made him rise to his feet after sealing in the enema water. The reflection of himself in the full-length mirror shocked him, never having seen the full extent of all the procedures inflicted on his body.

 

His cropped hair lay flat against head, his face was fuller and younger looking without his goatee. His body was no longer lithe and toned, now it was pale and soft without any muscle definition. His chest was puffy his thick erect nipples at least an inch long, his areolas has also spread, the darker skin highlighting his nipples. What shocked him the most was his large distended stomach, between the food overload and the enema he truly looked pregnant, his hand unconsciously rose to touch it, only to be knocked away by the vet.

 

“Naughty Pup, did I say you could touch? No, I did not, you will keep you paws by your sides unless I give you permission to move them.”

 

The vet stood behind a dazed Tony, erection pressing along his crack as he fondled and stroked the soft flesh of his pecs before tracing the line of nipples down each side of his full belly. Large hands pushed up his stomach, so he could see the full extent of the alterations to his cock, with only a few strokes of the vet’s fingers what was left of his cock plumped up and squirted clear fluid. Tears filled his eyes as he realised it was now as the vet had previously stated, nothing more than an overly large clitoris. A knee between his thighs had him leaning back against the vet’s chest as long fingers traced his newly formed piss hole, a sharp nail scratched the sensitive slit, sending a slither of arousal through his groin.

 

“Do you like that Tony, even pissing will get you excited now, the slightest touch along your perineum will get you whining for more, a finger brushing over your asshole will have slick leaking within moments

 

Such a dirty Pet, now be a good pet and lick my fingers clean.”

 

Slick coated fingers forced their way into his mouth, pumping in and out, he had no choice but to suck on them if he didn’t want to choke. The vet’s hard cock rutted against his crack, as fingers twisted and pinched his nipples before swiping more of the clear fluid leaking from his stubby cock to feed into his mouth. Limbs shaking with need he thrust his butt back against the thick cock sliding between his cheeks, lathing his tongue over the sweet tasting fingers.

 

“Such a needy little slut, you pets are all the same, you will do anything to get fucked by a big fat cock and you don’t even care if its human or another pet. Mindless animals no wonder you are not classed as human. Ruled by your base nature, unreliable, irrational and emotional stunted, it doesn’t matter how intelligent or successful you may be. When all is said and done, in the heat of arousal you would willingly sign your life and fortune away for an orgasm.

 

That’s why you need to have an owner, to keep you under control and train you. Bitches like you are especially flighty and need a firm hand, best way to keep you in line is to regularly mount and breed you. A belly full of pups and young ones hanging of your tits will keep you thoroughly occupied and out of mischief.”

 

Tony’s soft keens of pleasure filled the air as the vet’s fingers teased and caressed his body, the sharp cramps gripping his stomach forgotten as waves of pleasure crashed over him. The mirror clearly showing his flushed skin and hard nipples, glistening juices running down his thighs as his cock spurted uncontrollably.

 

The vet pushed Tony onto his hands and knees, after releasing his cock it only took a few tugs before he was shooting his load all over the pet’s flushed face. As much as he would have liked to continue playing with Tony Pup, he needed to get him cleaned up and settled so that he could finalise preparations for his two new guests that would be arriving within the next few hours. 

 

The vet stood back, admiring his handywork, Pup was encased in a thin, skin tight latex body suit, complete with hood and feeding muzzle, his stomach was swollen and heavy, pumped full of thick, slow releasing feeding gel to simulate the size and weight of a belly full of pups. The cramps he would suffer as the gel slowly passed through his digestive system would simulate contractions. Pup’s eyes were sealed, and his ears blocked, the only sound he would hear for the next few hours would be recordings of new born puppies crying for milk and a voice repeatedly ordering him to present his tits for his masters to milk. His nipples had small suction cups attached to give the sensation of pups feeding and hiss bitch hole was filled with an enormous plug that no matter how many times the stupid pet tried he would not be able to push it out. By the end of this training session Tony’s body would have been tricked in to believing he was pregnant, thus triggering his tits to start producing milk and with a few more sessions he would be fully conditioned to present himself, so his owners could drink his milk direct from his nipples.

 

After ensuring that the Pet was securely restrained within his crate, he proceeded to ready his lab for the arrival of his two new guests.

 

Tony lay on the soft mattress in the corner of the examination room watching as the vet set out trays of instruments beside the examination table and the surgical chair he had wheeled in to the room. His crate had been removed to make room for the dreaded chair. The vet had laughed when he had growled at it, telling him to behave or face having the hood and muzzle fitted again if he couldn’t be trusted to lay quietly and enjoy his temporary freedom from being confined and force fed. Tony quickly snapped shut his mouth, not wanting to be returned to the dark confines of the hood and the torturous cries of hungry pups, he was going to be a good pet and make sure that he didn’t anger the vet whilst he worked.

 

He must have dozed off as next time he opened his eyes the Vet was smirking at the two naked people strapped and gagged within two standing frames. Their limbs cuffed to each corner, whilst, thick collars with chin rests, attached to metal poles on each side of the frames held their neck and head in place. Keeping still and quiet, not wanting to attract the Vet’s attention he watched as the poor unfortunate couple’s transformations began.

 

“Leopold, I will begin with you, I am not going to lie, this injection is going to hurt, and you are going to be in agony for the next four hours whilst your latent pet gene is activated. You should have just agreed to be sterilised, then you and the beautiful Lydia could have carried on living a normal life. Instead you are solely responsible for Lydia’s coming transformation in to a slut pet for her step father, the Judge.

 

What’s that you are trying to say? Hmm can’t quite make out what you are saying with that ball gag stuffed in your mouth, still never mind its not of any importance to me anyway, nothing you can say will change your fate now.”

 

Tony cringed, squeezing his thighs together, covering what was left of his cock as the Vet stabbed Leopold’s ball sac with the huge needle, depressing the plunger quickly so that the enclosed fluid emptied in to the sac. He watched in horrified fascination as the man’s balls grew larger and larger until they hung between his spread thighs the size of tennis balls, the thick length of cock slapped up against washboard abs, the angry purple mushroomed head leaking precum as Leopold’s hips jerked back and forth.

 

“There we go, you are going to be consumed by a burning need to fuck and mate anything that moves, every fibre of your being will be seeking release, wanting to plant your seed and breed up all your bitches. Once your rut starts the latent pet gene will activate and full transformation will occur. Now let’s try and make this a little bit easier for you, would you like that Leo, want a warm hole to fuck, to shoot all your spunk in to? Want a needy little bitch hanging off your cock, belly swollen with your cum? 

 

Look at me Leo, not Lydia, she can’t help you, why would you want that stupid bitch, she is the one that has caused all this, ruined your career and life. If you had never met her none of this would have happened, I bet it was her that convinced you not to be sterilised and to stay together, probably wept crocodile tears to get her way. That selfish bitch deserves what is going to happen to her, step daddy is going to break her and punish her for her wilfulness and constant disobedience, she will never be able to harm and destroy another man’s life again.

 

Unfortunately, it is too late for you, but don’t you want revenge against her for reducing your life to that of a Stud Pet. Just think that whilst you will lead a pampered existence and have the satisfaction of giving life to your offspring, she will be nothing more then a series of fuck holes, used and debased by anyone the Judge gives her to.”

 

Tony watched as the bound man’s eyes strayed from his captured fiancée to him, lust and rage mingling in those sparkling orbs, as the ball gag muffled his roar of anger. The Vet’s order for him to present himself for oral training came as no surprise and he quickly crawled to kneel in front of the bound man, mouth wide open in readiness to accept the O ring gag the vet held in his hand.

 

“Good, Puppy, now place your hand’s on Leo’s thighs so I can guide his cock in to your mouth. There we go, now these straps will keep your hands in place whilst this head harness will ensure that you cannot pull back and release his cock, it will also limit the strength of Leo’s thrusts, after all we do not want him choking you to death as his cock increases in size as the serum takes effect. It will not take Leo long to build up a good rhythm, all you need to do is stay still and let him fuck your slutty mouth. The monitors I have placed on the pair of your will ensure that an alarm will sound if any of your vitals go over an acceptable limit.”

 

The Vet watched for a few minutes a Leo took to enthusiastically fucking Pup’s mouth, the serum was incredibly fast working if the latent pet gene was compatible, it was always a risk, the percentage of successful transformations was incredibly low, and the cost of synthesising the serum was prohibitively high. Only the multi-millionaires and billionaires of the world could afford it, time to upload Leo’s profile to the auction site, Leo had not seized on being injected, his balls had increased in size immediately and his cock had gone from limp and soft to rock hard within seconds. These were all the signs of compatibility with the serum, in less that four hours now he would have a rare Lion Stud, who would only need a few cosmetic adaptions before being ready for sale. As an added bonus it would be good training for Pup in deep throating, the little bitch’s gag reflex would be completely fucked out of him by the time the lion stud’s cock had grown to full size.

 

Now it was time to turn his attention to the lovely Lydia who had been crying hysterically since she had woken up bound and gaged to the standing frame. The Judge had specified what enhancements he wanted, none of which were overly difficult, nearly all could be achieved through injections and laser surgery. The longest would be the body tattooing as he wanted it done the traditional way, without any pain killers and in one sitting. The judge really wanted the girl to suffer, she had been a thorn in his side for years, never giving in to his advances, blackmailing him in to submission all the time her mother and his wife was alive after finding evidence of his many affairs.

 

Six months ago, his wife had died of cancer and the Judge was free of blackmail, having had a private detective follow the daughter to where she had stored the evidence against him after telling him she was going to release it to the press along with his taped conversation pressing her to split from her fiancé if they did not agree to him being sterilised so the latent pet gene could not be passed on. His chances of achieving a place as supreme court judge would have been ruined, but the stupid spoilt bitch hadn’t had the intelligence to cover her tracks and once the documents and tape had been secured, the trap had been sprung and both victims had ended up in his surgery.

 

“Lovely Lydia, shall we start with your transformation, your step father is eager to have you back in the bosom of your family. Both your uncle and aunt have expressed a wish to share in your training and re-education, the Judge has even agreed that your cousin Crispin can devise some of your more extreme punishments, its such good news that he has been granted release from the mental health facility he was placed in, in time to aid his family with the care of their new pet.

 

These first injections are going to increase the size of your breasts and nipples, your tits will be obscenely large 38F is the upper limit that your body frame will be able to support with the use of a corset with back bracing. Your aunt insisted that your nipples be elongated, pay back she said for the times you made snotty comments about her being a slut because of her nipples showing through her tops. Thick hard two inches in length teats coming up, and as a bonus, free of charge you will lactate when your nipples are continuously stimulated.”

 

The vet paid no attention to the muffled screams and pleas for him to stop, the injections took mere seconds, then it was time to move on to enlarging her clit and labia lips, the small laser scalpel cutting away her clitoral hood so her new fat juicy clit would be on display all the time. A weighted titanium ring would stretch it further and a simple chain could connect it to the anal piercing she would be getting. 

 

Next came the butt enhancement, he personally wasn’t a fan of the fad for huge Kardashian butt cheeks but each to their own and it would balance out the sizable increase in her breasts. After fingering her hole open, he slid the speculum in so he could inject the slick gland patches, her cunt juice production would also be receiving a boost. Ready and available to be fucked at any time without prep was always one of the most requested enhancements.

 

“Now whilst we are waiting for your breast and butt tissue to expand, we might as well start on your leg and arm tattoos, this injection cause temporary paralysis of your body, but you will still be able to feel every prick of the tattoo gun, the Judge was very insistent on that. Not often I am asked to free style, most buyers want precision laser work, snow leopard markings are not difficult and each one is unique. Once I have completed your legs and arms, I will fit your corset, your cousin wants to be the one to supervise your corset training, he has a bet with your uncle that he can reduce your waist to 20 inches within three months.”

 

The hum of the tattoo gun filled the room for the next couple of hours, the peace only disturbed by the occasional gagged moan from either Tony or Leopold. The vet smirked as Pup’s stomach grew huge and distended, far beyond any enema he had been given. Sweat, tears and snot covered the pet’s flushed face, but the needy bitch continued to whine and hump the transitioning lion pet’s leg, slick pooling on the floor between his spread knees.


	2. Chapter 2

**Summary for the Chapter:**

> Leopold and Lydia's transformation.
> 
> Pup's mouth gets a good workout.

Chapter 2

 

Checking the monitors, he noticed that Leopold’s heart rate was rising dramatically as his thrusts became more and more desperate and erratic as he chased the final orgasm that would pop his knot and complete his transformation. It was just as well, as he didn’t thing Pup’s Jaw and throat could survive much more fucking and there was no way he would be able to fit the Lion’s enormous knot in his mouth, he was proved right a few minutes later when the now un- gagged Leopold let out a loud roar as his knot expanded, battering at swollen bloody lips, desperate to gain entrance. In the end he had to be content with choking the Pup on his fully formed Lion cock.

 

Tony couldn’t catch his breath, the enormous cock filled his throat, the knot pressing up against his nose blocked his nasal airways, the straps tethering his head to the other’s groin meant he could not pull back more that a couple of inches in his desperate attempt to catch a breath to escape being suffocated. Black spots flickered across his already limited vision as he struggled in vain to break free, his stomach roiled as panic set in, his knees could find no purchase of the slick covered floor and his bound hands were numb and useless.

 

The vet watched with a sick sense of enjoyment and arousal Pup’s struggles to escape, only when he could see the pet was about to pass out did he release the straps of the head harness, yanking Pup’s head backwards until only the head of the enormous cock was still in his mouth, he allowed him a few quick gulps of air before forcing his head forward to once again swallow the enormous cock. The vet amused himself timing how long Pup could go before being on the verge of passing out through oxygen deprivation. 

 

“Pup you need to be able to take an Alpha’s knot in your mouth and breathe through the twenty to thirty minutes you will be knotted together. I am not going to stop this training until you can at least last five minutes without panicking or passing out, sync your breathing with your Alpha, as he inhales you need to take short shallow inhales through your nose. Over the next couple of days until Leopold is auctioned, he is going to be fucking your throat raw, it will improve both of your stamina.”

 

Once Pup had successfully lasted five minutes, the vet in a rare moment of compassion for the wrung out, pet, allowed him to crawl back to his bed to sleep. Once the exhausted pet has passed out he inserted the feeding gag into the o - ring, turning the pump to high, the pet’s weight needed to reach the target set before the Avengers returned, the distraction of his new guests had meant Pup had missed his previous four feeding sessions, the sedative in the first batch of feed would keep him under whilst he completed all the procedures on the Judge’s step-daughter and the new Lion Stud.

 

Leopold’s procedures were mainly cosmetic, the vet smirked as he injected the Stud with a rapid hair grown serum, within three hours his facial hair would that of a full beard and by morning he would have a thick wild mane of tawny blond hair. The Lion’s body weight would increase, and his muscles would naturally bulk up over the next few days, his flanks and legs would be covered in a layer of fine hair in shades to match his head hair and beard. 

 

“You are going to be such a fine specimen for the auction tonight, the biding war is going to go through the roof. Your new owner will have the option of further enhancing your body, may be a tail, or vocal alteration, surgery to make your facial features more lion like, or even adapting your hands and feet to mimic a lion’s paws.”

 

The vet hefted the huge semi hard cock in his hand, his other hand fondling the dangling ball sac.

 

“Need to get some photos of this bad boy for the buyers, they will all want to see your knot and proof that you are producing semen. We will give if a couple of hours as you have not completely finished transitioning and will probably get larger and your balls will drop further as the weight stretches your sac.

 

Right time to move on to the lovely Lydia, wouldn’t want her to feel that she is not getting any attention. Time to fit your corset my dear, your waist is going to look stunning, Crispin has devised a strict training regime to ensure your waist is reduced to 20 inches.

 

The silver, grey leather and whale bone corset looked stunning against her pale tattooed skin the vet managed after a bit of a struggle to decrease her waist size down to twenty- four inches from twenty- six. The corset started just under her breasts and ended on the flare of her hips, emphasizing her large plump butt cheeks.

 

“Right, let’s get those tits and shoulders tattooed whilst Leopold fucks Pup’s mouth again, by the time I have finished Leopold will be ready for his cum and knot photos and Pup will be a pro at deep throating, pity I can’t risk him knotting Pup’s mouth, don’t want to upset Captain Rogers by having his Pet choke to death.”

 

Hours later the vet stepped back to admire his finished work. Lydia’s skin was covered in grey, silver and white snow leopard spots, a thin trail ran up the sides of her face and across her cheek bones, highlighting the heavy titanium nose piercing. Permanent dye had changed her irises to an ice blue with a silver ring around them. Her long blond hair had been cropped short on top and bleached white, the shaved sides had a silver and white fade.

 

He tweaked her thick nipples until a steady stream of milk flowed across her enormous breasts, dripping down on to Pup’s head, who was busy eating her out, face liberally covered in her cunt juice. The vet watched as Leopold struggled in his bonds, unhappy that his cock sucker was pleasuring someone other than him, his cock straining and dripping pre cum, knot still not having receded. The photos he had uploaded were stunning, the Lion Pet’s 13inch cock and knot shooting cum over the face of a kneeling Pup, thick ropes of cum liberally coating the pet’s face and chest. The photo the vet kept for himself was a close up of Pup’s desperate, terrified eyes as Leo’s knot smothered his mouth and nose, slowly suffocating him.

 

“Come here Pup, time to put all my Pets to bed for the night, tomorrow will be a big day for Lydia, as she will be going home to the Judge, but don’t worry Pup, Leo will still be here until he is shipped out to his new owners, whoever they may be. Plenty of time for you to practice with your slutty mouth ready to take your own Stud’s knot.”

 

The vet was ecstatic when the biding finally closed at midnight, Leopold had sold for $10, 000 000. His new owner had also paid another $500,000 for the further enhancements he wanted. Leopold would be shipped out in twenty-four hours, with modified vocal cords so that he could growl and roar but not speak, facial features altered to appear more lionesque, thick pebble nipples pierced with gold bars and the implanted stub that would grow into a lions tail within weeks. 

 

The Sheik who had purchased Leo, was a well know breeder of exotic Pets and the vet could only imagine that he had already purchased the more easier to find Lioness Pets, the buyer had purchased a rare female White Tiger Pet from him two years ago, if successfully cross bred the cubs would sell for an exorbitant price.

 

Tony sighed with relief as he watched Leo’s crate disappear into the elevator, his jaw ached, and his stomach roiled with the copious amounts of cum he had swallowed over the previous two days. Perhaps now he would be allowed to rest, he almost was looking forward to being placed back in his crate. 

 

He wondered how Lydia was faring, the poor girl was doomed to playing the part of pet for the rest of her life, a fuck toy for her family, and no one who knew her before would ever realise who she was, the physical alterations ensured that as well as the ball gag that she would always wear in public. The vet had said he would not be surprised if Lydia who was to be called ‘Snow Gem’ from now on would be back for further enhancements, to alter her facial feature to make her appear more cat like.

 

“Well Pup, its just you and me again, Captain Rogers and the Avengers will be back at the end of the week, and they are bringing back a surprise for you. They have managed to track and capture the Winter Soldier, there has been an unexpected development, so they are bringing him to me for treatment as Captain Rogers is afraid that if the authorities find out they will take him into custody and he will lose Bucky completely.”

 

Tony was confused, what did Cap’s dead best friend from the war, have to do with anything, he whined at the vet though his gag, wanting an explanation.

 

“Oh Pup, did I neglect to tell you that Sargent Bucky Barnes is the Winter Soldier, captured by Hydra after he fell from the train and experimented on to create the Winter Soldier/Winter Wolf.

 

Now let’s get you situated in your crate, going to fix you up so you are knotted constantly at both ends in preparation for your Stud. You may not have been able to fit Leo’s knot, but your pretty little cock sucking lips will open wide enough by Friday to take the Winter wolf’s knot.”


End file.
